Switch particularly adapted for speedometer solenoid actuation



A ril 20, 1965 R. M. DYKSTERHOUSE 3,179,765

SWITCH PARTICULARLY ADAPTED FOR SPEEDOMETER SOLENOID ACTUATION FiledJan. 25, 1962 2 Sheets-Sheet 1 April 1965 R. M. DYKSTERHOUSE 3,179,765

SWITCH PARTICULARLY ADAPTED FOR SPEEDOMETER SOLENOID ACTUATION FiledJan. 25, 1962 2 Sheets-Sheet 2 United States Patent SWlTCI-IPARTICULARLY ADAPTED FGR SPEEDOMETER SQLENQID ACTUATHON Robert M.Dylrsterhouse, Charles/nix, Mich, assignor, by mesne assignments, toCircuit Controls Corporation,

Petoskey, Mich, a corporation of Michigan Filed Jan. 25, 1962, Ser. No.168,6b2

3 Claims. (Cl. 200-6158) case or housing is also important because itprovides a a direct means for linkage with a speedometer control elementor the like. The manually operable control element is selectivelyengageable with the operating pin of the switch as the control elementis moved in .a tubular sleeve. Movement of the control member causesselected shouldering of the switch operating pin thereby closing thecontactorof the switch. When the speedometer control element is moved:away from shouldering engagement the switchleaf, in obedience torelease pressure upon the operating pin, returns the contacts to an openposition with a quick pick oif from the contactor. Simultaneously, thepin, in following relationship with the control member repositionsitself for repetitive operation.

Many mechanical, electrical, pneumatic and hydraulic devices require acompound form of control as for example, where a limited lineal movementis necessary from a position remote from the actual work and where anelectrical circuit, for example, must be coordinated with the mechanicalor lineal motion. An example occurs in trucks where the selection of anew speed range of gearing requires the energization of a separatespeedometer. One portion of the action is mechanical or lineal. The

other portion of the action is electrically controlled. In

general, such situations are met by providing a limit switch which isenergized or tie-energized upon motion would result in a labyrinth ofwiring clutter. Ideally such controls should be located proximate to acentral control panel adjacent to the location of the control elementwhich must be manually acted upon by the driver, for example.

The present switch is particularly adapted for inside location at aselected position along the line served by a push-pull cable connectionas exemplified in Bowden wire systems. The switch employs a straddlecasing which hosts neatly upon a tubular sheath in ferrule encasing anactuating piston tor reciprocatingthe central control wire in a Bowdenwire structure. The piggy-back construction adapts the switch for easyoriginal installation and replacement .or service; While especiallyadapted to use with transmission selection mechanisms for speedometerfsole'noid actuation, the switch of the present invention hasinnumerable other ,uses where Bowden wire actuation re- 'quirescoordinated electrical energization and deenergizalice tion. Further,the present invention utilizes a switch spring action completelyadequate for pin return without auxiliary spring return and doing soover a long life because of its great simplicity and minimum throw. Inaddition, the particular leaf spring action is very last in avoidance ofarcing at closing and opening of the contacts.

In usage the switches have shown excellent trouble free longevityoutliving the Bowden wire systems into which they are integrated.

Accordingly the principal object of the present invention is to providea unique switch unit for straddle positioning.

Another object is to provide a micro-type switch for integrating with aBowden wire actuating system coordihating electrical control with linealmovement at or adjacent to the lineal actuation control member.

Another object is to provide a unique fast acting switch 7 structurewherein the case prov-ides a stop limiting full throw of the contactactuating leaf. and wherein the light spring action in the leafaccomplishes following return of the actuating pin without auxiliarysprings or mechanism.

Still another object is to provide a suitable switch having long lifecharacteristics which'is simple to fabricate and easy to install andmaintain.-

Other objects including overall adaptability to coordinating Bowden wireactuation with selected actuation of electrical circuits and attendanteconomics resulting from the availability of such deviceswillbeincreasingly clear as the description proceeds.

In the drawings:

FIGURE 1 is a side elevation view of a Bowden wire tubular ferrule andshowing the switch of the present invention in piggy-back position'astraddle the ferrule.

FIGURE 2 is another side elevation view and illustrates the ferrule ofFIGURE 1 with a portion removed to illustrate the Bowden wire actuatingpiston reciprocably in the terrule.

FIGURE 3 is a partial cut away portion indicating piston engagement withthe switch actuating pin causing selected movement of said pin.

FIGURE 4 is a top plan view of the switch in mounted position and inhidden edge indicating the position of the opening through the ferrulewall.

FIGURE 5 is a full cross section elevation view taken on the line V--Vof FIGURE 4 and indicating the simple case construction dimensionallyrestricting the throw of the leaf spring element and indicating theswitch in the open position.

FIGURE 6 is a detail of the cross section shown in FIGURE 5 andindicating the piston engagement and movement of the actuating pin toclose the switch contacts.

FIGURE 7 is an exploded perspective view indicating the extremesimplicity of the switch.

General description In general the present invention comprises a leafspring type actuation structure positioned by an upper encasement andhousing member, both of these elements being prepared as by molding fromhigh dielectric strength resin material. ,Upper and lower as thus usedhas reference to the FIGURE 1 orientation of the structure and as willbe appreciated, this positioning may be reversed since the structure isoperative from any selected location. The casing is adapted for straddlemounting over a tubular member, as for example a ferrule guidingreciprocating lineal movement of a piston element. A transverse openingis provided through the wall of the ferrule member and the actuation pinof the switch then depends or extends into the tube transversely of theaxis of the tube.

This extension is adequate so long as it provides for an actuatinginterference with the lineally moving member or piston element. Locationof the switch in straddle position is selected in accord with a desiredpoint in lineal movement where coordinated electrical circuits requirecoordinated energization or deenergization. Overrun movement has noeifect on the switch provided the piston is of uniform cylindricaldiameter. Selected upsets on the piston may be provided to establishzones of energization and deenergization where this is required sincethe actuating pin maintains following contact with the piston.

Until contact, as between piston element and switch pin, the switchoccupies a normal (open or closed-shown open) position biased by theactuating leaf mechanism. The switch leaf actuating mechanism is movedagainst this bias by movement of the pin in accord with the pistonengagement. Here the switch case provides an insulating blockage orlimit to overrun of throw. This movement of the leaf urges a snap actioncontact movement in avoidance of arcing at the contacts. The leafactuation structure and contactors are contained in two strips of flatspring stock as ordinarily selected for electrical equipment such asberyllium-copper alloys having good fatigue resistance and excellentconductive characteristics. Intermediate the two leaf elements aninsulating block is provided for spaced retention of the leaf elementsat one end and leaf elements and spaces are in turn sandwiched betweenthe upper and lower insulating case elements.

The elimination of full throw by the leaf assures good operating bias onthe actuating pin, gives excellent fast break action at the contactorsand provides a longer life than anticipated in most bow type springswitches. Further, the switch is easily installed and easily integratedinto existing wiring harness arrangement. It has proved very serviceablewith Bowden wire type devices.

Specific description Referring to the drawings and particularly toFIGURE 1 thereof, a switch 11 in pig-a-back relation to a tubularferrule 12 is shown in accord with the present invention. Electricalleads 13 and 14 are shown entering the switch cover 15, the leads 13 and14 being generally parallel to the tubular ferrule 12. The base portion16 of the switch 11 is provided with clevis legs 17 which straddle thetubular ferrule 12. An actuating pin 18 intermediate the clevis legs 17,and extending transversely through the base member 16, is provided whichdepends into the axial cavity of the tubular ferrule 12. As will beseen,the actuating pin 18 is biased axially so as to resiliently follow themovement of a member guided by the guide ferrule 12. As shown in FIGURE1, the resilient bias has been overcome and the pin 18 is fully extendedinto the switch 11.

By reference to FIGURE 2 the guide ferrule 12 has been cut away toreveal its tubular character and the control piston element 19 is shownin the cavity 241 of the tubular ferrule 12. As will be appreciated, thepiston element 19 is reciprocable axially in the ferrule 12 as by manualpush-pull action on the control knob 21 secured to the piston element19, limited in its travel by shouldering engagement with the ferrule 12.

Such an arrangement is characteristic of Bowden wire remote controlcable actuating arrangements and the piston 19 is shown connected to acable element 22 which reciprocates in accord with the piston 19 andcorrespondingly moves lineally in the sheath 23. A grommet element 24establishes a crimp sleeve connection with the sheath 23. The sheath 23as will be appreciated is flexible and houses the cable leading to aremote connection with mechanism (not shown) to be acted upon by thelineal stroke of the cable or core piece 22. Where, for example, thecable or core piece 22 activates a separate transmission, it isdesirable that cooperating gauges and indicators, as for example,speedometers and solenoids therefor be energized. Other functions mayalso require electrical coordination but the specific application ismentioned as typical. By reference to FIGURE 3 the actuation of theswitch 11 is understood in reference to the relationship between theactuating pin 18 and the piston 19 in the guide sleeve or ferrule 12.The actuating pin 13 radially depends into the cavity 20 of the ferrule12 and through the opening 25 provided through the tubular wall of theferrule 12. The pin 18 hence depends into an interference position withthe stroke of the piston 19. The tip 26 of the pin 18 is rounded so asto accomplish radial and axial movement as the chamfer 27 on the end ofthe piston 19 engages the pin 18. The pin 18 is thus deflected against aresilient bias as will be seen as the description proceeds to accomplishselected energization or deenergization of the circuit served by theswitch 11. The resilient bias on the pin 18 continues so that contact asbetween pin 13 and barrel of piston 1% is maintained. When the piston 19is withdrawn from contact with pin 18, the pin 18 is returned to itsinitial rest position as shown in full line in the FIGURE 3.

In FIGURE 4 the switch 11 is shown in top plan view astraddle theferrule 12 with the depending legs 17 flanking the ferrule 12 so as tolocate the actuator 18 in register with the opening 25 defined in theferrule 12 so as to provide an interference contact as between the pin18 and the piston 19. Fasteners 28, such as rivets or screws, secure thecover 15 to the base member 16.

In the cross section as shown in FIGURE 5, the switch 11 is opened upalong its elongate axis to reveal the switch cavity 29 as definedbetween the cover element 15 over the base member 16. The clevis legs 17depend from and are integral with the base 16. Registering openings 30through the legs 17 provide simple clamp means as by a fastener (notshown) passing through both and bearing on the ferrule 12. The cover 15is made from insulating material which is cast or otherwise molded asfrom resin materials such as the urea formaldehydes, nylon or the likehaving adequate dimensional stability. The cover 15 is molded to closeover the base 16 and shoulder thereagainst. Cradle-like bracketextension 31 and 32 at each end of the base 16 provide for locatablymounting the switch 11 to the ferrule 12 as previously seen. The cover15 is also provided with a stop extension 33 in axial register with theactuating pin 18. This, as will be seen, limits full throw of theswitch. In addition, a boss 34 is integrally and internally provided atone end of the cover 15. The base member 16 provides a platform-likebottom 35 to the switch 11 and the opening 36 is provided transverselytherethrough intermediate the legs 17, the opening 36 journalling thepin 18 which extends therethrough. A first contact carrying lead plate37 rests registrably on the platform surface 35 of the base 16. Theplate 37 is an elongate flat piece of conducting material electricallyconnected to the lead 14 at one end and provided with a first contactor38. A second contact carrying lead plate 39, having an integral bowportion 40, is positioned in substantially spaced apart parallelregister with the first contact plate 37. The bow 40 is positioned inregister with the pin 13 on one side and the abutment or stop 33 on theother side. As will be appreciated, the stop 33 thus limits the amountof movement of the second plate 39 at the free end 41 thereof bylimiting movement of the how 40. The free end 4-1 of the plate 39carries the contactor 42 which is hence movable with movement impartedby the bow 49 oscillating in accord with movement of the pin 18. Thesecond contactor plate 39 is of the leaf spring type and the bow 40 isformed by parallel elongate slots 43 (FIGURE 7) provided in the plate39, the bow portion as, intermediate the slots 43 then being deformed toprovide a selected bow spring bias acting upon the entire leaf. Theaction of the moving contact plate 39 is best understood when it isappreciated that the end 44 thereof, opposite the free end 41, is fixedin spaced parallel register with the corresponding end of the firstcontactor plate 37.

Spacing is by means of spacer block 45 comprising an insulating waferbetween the movable contactor element 39 and the fixed contactor plate37. One of the fasteners 28 is thus seen to pass transversely throughthe cover 15, second contactor plate 39, spacer 45, first contactorplate 3! and base 16. Parallel registry is hence maintained by thefastener 28 and the limiting confines of the switch case comprisingcover and base 16. The boss 34 of the cover 15 thus bears upon thesandwich arrangement of contactor carrying elements spaced apart by thespacers 45. The lead 13 thus passes into the switch cavity 29 and iselectrically connected to the leaf spring contactor element 39 adjacentthe spacer 45.

By reference to FIGURE 6 the detail view shows the contacts 42 and 38 inclosed position in contrast to the open switch position shown in FIGURE5. In FIGURE 6 the switch 11 is positioned astraddle the ferrule 12 andthe pin 18 extending through the opening 36 in the base 16, and throughthe opening 25 in the ferrule 12 has been moved by action of the piston19 so as to overcome the spring bias of the bow .40 thereby causing theleaf spring element 39 to snap closed toward the contactor plate 37bringing the contactors 42" and 38 into conducting relationship. In thisaction the amount of movement of the bow 40 toward full over centerthrow is limited by the stop 33 thus maintaining closure of the contacts42 and 38 while axially exerting spring pressure on the pin 18 urging itinto following contact with the piston 19. Hence, as the piston 19 isbacked oif from contact with the pin 18, the switch 11 snaps open as inFIGURE 5, the pin 18 then radially extends into the opening in theferrule 12. Hence, as will be appreciated, the positioning of the pin 18and the attendant location of the switch 11 admits of considerablecoordination with lineal piston movement by the simple expedient oflocation of the straddler switch 11 at a selected location along theferrule 12.

The simplicity of the switch 11 is best understood by reference toFIGURE 7 where the switch 11 of the present invention is shown inexploded view. Four cast or molded insulating elements are required, thecover 15, the base 16, the spacer 45 and the pin 18. The conductingcontactor carrying elements 37 and 39 are easily attachable to leads 14and 13, respectively, with spacer 45 located therebetwcen and the wholeswitch 11 is then assembled by dropping the pin 18 through the opening46 transversely through the contactor plate 37, the head 47 on the pinlimiting drop through, and then closing the whole switch mechanismbetween the base 16 and cover 15 and fastening the whole by use offasteners 28. Flank shoulders 48 in the cover 15 assure alignment of theelectrical conducting members along with the locator elements 49 and 50in the base 16. These locator elements 49 and 50 index the position ofthe contactor plate 37 on assembly. Step 51, provided at one end of theplatform surface 35, provides an insulating relief for the lead 14serving the plate 37 when viewed in cooperation with the spacer 45. Asimilar step 52 is provided in the spacer 45 to insulate and accommodatethe lead 13 connecting with the second contactor plate 39.

The switch 11, in summation, is thus seen as a compact and simplestructure wherein only two moving parts are involved and wherein theleaf spring element is limited against full throw with resulting longlife and dual function. In this connection the bow serves to move thecontactor into and out of conducting relation with its fixed counterpartand also serves to relieve the pin when overcoming bias is relieved. Theelements of the switch 11 are easily and economically fabricated and theresultant switch product supplies a long felt need for electricalcoordination with lineal acting mechanical components such as Bowdenwire systems. Installation and selection of switch location is verysimple by the mere radial piercing, for example, of a Bowden wire guidesleeve or ferrule. Replacement and repair is easily accomplished. Switchperformance is very good and contact pressures as between the pin 18 andpiston 19 are minimal so that wear at this point is no problem.Fabricating of the switch requires no special skills and assembly isrelatively fool-proof. By securing elements 37 and 39 to wire harnessand field assembling these elements to form the switch 11 it ispossible, where desirable, to attain ultimate installation advantage.

Having thus described my invention those skilled in the art will readilyperceive additional modifications, changes, and improvements therein andsuch modifications, changes, and improvements therein are intended to beincluded herein limited only by the scope of the hereinafter appendedclaims.

I claim:

1. A switch comprising:

(a) a base member of insulating material and provided with a platformportion and depending clevis portion;

(15) a cover member of insulating material registrably positioned tocover said base member and shoulder thereagainst while definingtherewith a mechanism cavity;

(c) a fiat contact plate secured to said platform portion of said basemember and held by said base and said cover against movement;

(d) a flat leaf spring contact element having an integral bow portion,said leaf spring contact element positioned in said cavity defined bysaid base and said cover and in substantial parallel registry with saidflat contact plate;

(e) a spacer block provided at one end of said cover member and spacingapart said flat contact plate and said flat leaf spring contact elementat one end;

(1) an actuating pin transversely through said base and between saidclevis depending from said base in biased contact with said bow portionof said leaf spring contact element and having positively limited axialmovement said axial movement in one direction depressing said howportion of said leaf spring contact element thereby accomplishing a snapaction engagement between said flat contact plate and said leaf springcontact element.

2. The structure of claim 1 and including: a member lineally betweensaid clevis depending from said base in an interference path with saidactuating pin and overcoming said bias applied by said integral bowportion to said pin, thereby selectively operating said leaf springcontact element.

3. The switch structure of claim 1 and including:

(a) a guide ferrule lineally between said clevis and in compact parallelrelationship with said base member; and

(b) a piston reciprocable in said guide ferrule, said piston in aninterference path with said actuating pin and overcoming said biasapplied by said integral bow portion to said actuating pin, so as toselectively operate said leaf spring contact element.

References Cited by the Examiner UNITED STATES PATENTS 1,561,432 11/25Hitchcock 248-230 1,826,105 10/31 Veale 200-161 2,448,230 8/48 Miller200-67 2,545,264 3/51 Davis 200-67 2,700,079 1/ 5 5 Haydon 200-672,790,863 4/57 Towle 200-161 2,838,622 6/58 Bachi 200-153 2,840,65 6 6/5 8 Roeser 200-67 3,120,590 2/ 64 Dahlin 200-67 BERNARD A. GILHEANY,Primary Examiner. ROBERT K. SCHAEFER, Examiner.

1. A SWITCH COMPRISING: (A) A BASE MEMBER OF INSULATING MATERIAL ANDPROVIDED WITH A PLATFORM PORTION AND DEPENDING CLEVIS PORTIONS; (B) ACOVER MEMBER OF INSULATING MATERIAL REGISTRABLY POSITIONED TO COVER SAIDBASE MEMBER AND SHOULDER THEREAGAINST WHILE DEFINING THEREWITH AMECHANISM CAVITY; (C) A FLAT CONTACT PLATE SECURED TO SAID PLATFORMPORTION OF SAID BASE MEMBER AND HELD BY SAID BASE AND SAID COVER AGAINSTMOVEMENT; (D) A FLAT LEAF SPRING CONTACT ELEMENT HAVING AN INTEGRAL BOWPORTION, SAID LEAD SPRING CONTACT ELEMENT POSITIONED IN SAID CAVITYDEFINED BY SAID BASE AND SAID COVER AND IN SUBSTANTIAL PARALLEL REGISTRYWITH SAID FLAT CONTACT PLATE; (E) A SPACER BLOCK PROVIDED AT ONE END OFSAID COVER